A. Field of the Invention
This invention relates generally to hinges, and in particular to a pressure hinge that can be used to hinge a glass panel door to a glass panel wall or to a wall of other material, shape, or orientation with respect to the door.
B. Problems in the Art
The need for a device to hinge glass, and particularly unframed glass, was largely spawned by the rising popularity of frameless all-glass shower enclosures. A variety of devices have been used to hinge glass panels. Continuous improvements have been made in an effort to design a hinge that minimizes fabrication and installation costs, allows for a wide range of rotation with consistent return to its original position, is of high quality, and is aesthetically pleasing to the user.
It is not a trivial matter to design a hinge that meets these goals. Glass is relatively heavy. It is not easily modified, for example, by drilling holes through it or even cutting into it.
One device commonly used is a hinge that fastens to the glass through holes drilled in the glass. Specifying that holes be made in the fabricated product is undesirable. Such a design is less flexible in that once the holes are drilled, the exact location of the hinge cannot easily be adjusted. Consequently, greater accuracy by the installer is required in the field, measuring and installing of the fabricated glass. Also, the fabricator and temperer of the glass must be accurate and capable of great detail. Thus, using a hinge that requires holes in the glass results in a more expensive process. Holes can also present potential breakage problems.
Other hinge designs clamp onto the glass to eliminate drilling through the glass. These hinges, however, suffer from a variety of problems. One common problem in the prior art is the inability of the device to maintain a secure grip on the glass. If the clamp on the hinge does not firmly grip the glass, loosening or misfitting can occur. If additional torque is applied to the clamp screws to attempt to establish a secure grip, more stress and strain is placed on the glass panel. Furthermore, applying additional torque results in a more difficult, time consuming and expensive installation.
A second problem involves the inability of the prior art to consistently return a glass door panel during rotation to certain predetermined angles. It is frustrating to a user to open and close a glass door which does not index with such absolute repeatability.
Another problem in the prior art concerns the design of internal parts of the hinge. Many of the devices have internal parts that rub or experience forces which tend to wear out their internal mechanisms. When the internal mechanism begins to wear, the hinge can lose its accuracy and become less effective.
Most hinges currently used are made of a non-corrodable metal (e.g., brass, stainless steel, aluminum) because of strength and durability, and because the hinges will constantly be exposed to moisture and humidity. The prior art is plagued, however, by grain structure flaws. It is commonplace to utilize forging methods to manufacture a glass door hinge. Inherent in such a method are flow control problems that result in grain structure flaws. These structural flaws weaken the hinge body with the hinge tending to lose its accuracy and become less effective.
Another widespread problem exists when the prior art is used to hinge a glass door panel to a wall. Typically, the base plate mounted on the wall and the main body of the hinge are designed with abutting flat surfaces. This design is susceptible to a rocking motion when the hinge rotates, which tends to loosen the base plate screws under an axial load.
Finally, the prior art tends to suffer from a lack of aesthetic appeal. Glass panels and doors are often incorporated in designs for their aesthetic qualities. A hinge that subtracts from the aesthetic appeal of its environment may not be desired even when functionally adequate. For example, if the environment is a frameless all-glass shower enclosure, consumers are likely to prefer a metal hinge with a lustrous finish over a hinge with a dull finish or a hinge with a minimum number of protrusions or visual interruptions.
All the prior art suffers from one or more of the aforementioned problems. Thus, there is a need in the art for a hinge that can firmly grip glass surfaces in a way that minimizes costs, achieves absolute repeatability in indexing, is durable, easy to install, and is aesthetically pleasing.
It is therefore a principal object of the present invention to provide a device and method which improves over or solves the problems and deficiencies existing in the art.
It is a further object of this invention to provide a device and method which firmly grips glass doors and panels.
It is a further object of this invention to provide a device and method which hinges glass panels in a way that permits for a wide range of rotation with absolute repeatability in indexing.
It is a further object of this invention to provide a device and method which minimizes structural flaws.
It is a further object of this invention to provide a device and method which deters the loosening of the wall plate screws when a glass panel is hinged on a wall.
It is a further object of this invention to provide a device and method that is aesthetically pleasing so as to compliment its environment.
It is a further object of this invention to provide a device and method that minimizes fabrication and installation costs.
It is a further object of this invention to provide a device and method that is durable.
These and other objects and advantages of the invention will become apparent to those skilled in the art with reference to the accompanying claims and specification.